1. Field of the Invention
The invention relates to a method of charging fine-grained ore, in particular iron ore, into a reactor pressure vessel through which process gas flows, wherein the ore at first is introduced into a conveying pressure vessel, is pressurized within the same by means of a compressed gas and subsequently is conveyed into the reactor pressure vessel through a conveying duct by means of the compressed gas, as well as an arrangement for carrying out the method.
2. Description of the Related Art
It is known to provide a pressurized sluice system for charging fine-grained iron ore into a reactor pressure vessel (U.S. Pat. No. 5,082,251). In doing so, the fine ore at first is filled into a pressure vessel, which, upon closure of the feed duct to the reactor pressure vessel, is brought to the pressure of the pressure reactor. After this, the outlet duct to the reactor pressure vessel is opened and the fine ore flows into the reactor pressure vessel by means of gravity. Charging in this manner may be effected both at ambient temperature and at elevated temperatures. The spatial arrangement of such pressurized sleuce systems is possible only above the pressure reactors because of the utilization of gravity. This calls for a large structural height of the whole system and hence for great structural expenditures as well as complex conveying means.
From the Journal of Metals, April 1957, pp. 586 to 590, "The H-Iron Process", a method of the initially defined kind is known, in which hot fine ore is introduced into a conveying pressure vessel pneumatically via a collecting tank. As soon as the conveying pressure vessel has been filled, it is pressurized by means of hydrogen gas, which, in that case, serves as the process gas for the reduction of iron ore, whereupon the conveying duct between the conveying pressure vessel and the reactor pressure vessel is opened. As a result, the fine ore flows into the reactor pressure vessel within a short span of time. Such discontinuous charging adversely affects the reduction process. Nonuniform qualities are obtained, and the reactor pressure vessel is unevenly stressed at an unfavorable utilization factor.
From EP-A-0 027 909 an arrangement for continuously conveying fine-grained stock, such as coal dust, is known, which comprises two pressure vessels to be alternately filled and emptied pneumatically, from which the stock to be conveyed is continuously supplied to the consumer by aid of compressed air. The compressed air used is ambient air fed via a compressor to the conveying ducts conveying the stock to be conveyed and, thus, to the coal dust consumer. The apparatus is complicated and does not provide continuous operation of a reactor vessel.